Artificial reproduction and reproductive parameters of silver catfish Schilbe intermedius (Siluriformes: Schilbeidae) – implications for the conservation and domestication of this threatened species.

The silver catfish Schilbe intermedius (Rüppell, 1832) is single-spawning species spread in Africa and may reach 50 cm in length. Since there are no studies on the artificial reproduction of S. intermedius, the aim of the present study was to induce for the first time spawning by hormonal injection and to determine the reproductive parameters for this species. Artificial induction was carried out by the injection of Ovaprim (0.5 ml kg− 1) to males and females. Different eggs measurements were carried out by micrometer. Egg stripping was carried out ten hours after hormone injection at 27.17 ± 0.22 °C (mean ± standard deviation) with mean spawning rate 58.15 ± 2.88 %. Relative fecundity was 613.25 ± 71.83 oocytes/g with mean diameters 0.94 ± 0.10 mm and 1.11 ± 0.06 mm, respectively, before and after eggs fertilization. Fecundity and hatching rates ranged, respectively, from 60.30 to 68.02 % and 56.11–60.96 %. Egg hatching occurred about 22 or 28 h after fertilization at 26.02 °C, and the larvae average length was 1.24 ± 0.14 mm. Yolk sac resorption occurred 48 h after hatching and larvae acquired their morphological structures in about 72 h after hatching. This information will be important in improving the artificial reproduction protocols of S. intermedius in controlled breeding programs. [ABSTRACT FROM AUTHOR]